This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X1250S, with the same bore, stroke, output force, port and mounting, so it fits the same application. The SAI replacement keeps the same ISO 15552 mounting interface, bore, stroke, output force and accessories, so it drops straight into existing fixtures. It is the current-production version of this cylinder with an upgraded piston seal.
Airtac SI50 Standard Cylinder SI50X1250S
The AirTAC SI50 Standard Cylinder SI50X1250S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 1250mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X1250S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke1250 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X1250S
- No minimum order. A single piece can be ordered.
- Ready in 3–5 business days. That is the time we take to process the order and hand it to the carrier. Transit time after that depends on the destination.
About the Airtac SI50 Standard Cylinder SI50X1250S
The AirTAC SI50X1250S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 1250mm stroke. Generating 982N push force at 0.5MPa, it features a G1/4 air port and a magnetic piston for CS1-B/DS1-B sensors. Because 1250mm exceeds the 1200mm standard maximum, this is a non-standard made-to-order length. AirTAC replaced this EOL unit with the SAI50X1250S.
The SAI50X1250S is a direct replacement, retaining the exact ISO 15552 mounting interface, bore, stroke, force, and port size. The upgrade introduces a two Y-shaped one-way piston seal for lower start-up pressure and longer life. For load holding, note that a plain cylinder drifts without air; use an external rod lock or the SAIL/BSAI lock variants.
Airtac SI50 Standard Cylinder SI50X1250S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X1250S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X1250S |
| Bore size | Ø50 mm |
| Stroke | 1250 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| Rod thread | M16×1.5 |
| Fluid | Air (filtered by 40µm element) |
|---|---|
| Operating pressure | 0.15 – 1.0 MPa |
| Proof pressure | 1.5 MPa |
| Temperature | -20 to +70 °C |
| Speed range | 30 – 800 mm/s |
| Cushion | Adjustable, 30 mm |
| Max standard stroke | Up to 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI50X1250S carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø50mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 982 N | 825 N |
| 0.7 MPa | 1374 N | — |
| Max (@1.0 MPa) | 200 kgf | |
The SAI50X1250S produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI50 Standard Cylinder SI50X1250S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×1250 | Stroke length in mm. |
| -S | Optional built-in magnet for sensor position sensing. |
Legacy SI-family variants: SID (double rod), SIJ (adjustable stroke) — each maps to its SAI equivalent (SID→SAID, SIJ→SAIJ). Rod material: carbon steel (blank) / SUS420J2 (A) / SUS304 (B).
Where the Airtac SI50 Standard Cylinder SI50X1250S Is Used
Long-Stroke Transfer
Moves components between workstations over a 1250mm span where standard lengths fall short.
Automated Positioning
Shifts tooling carriages into machining zones using the magnetic piston for end-of-travel sensing.
Replacing the Airtac SI50 Standard Cylinder SI50X1250S with the SAI50X1250S
To replace the SI50X1250S, order the SAI50X1250S direct equivalent, verifying your ISO 15552 mounting accessory (LB, FA, TC, etc.), G1/4 port thread, and the -S magnet requirement. The SAI family uses current AirTAC switches instead of the legacy CS1-B/DS1-B set. If sizing down, a 40mm bore yields 628N push at 0.5MPa; sizing up to 63mm provides 1559N. Because the 1250mm stroke exceeds the 1200mm standard, it is made-to-order and requires an external guide to prevent rod bending and excessive side-loading. Remember that standard cylinders do not hold load on air loss—select the SAIL or BSAI lock variant, or a pilot check valve, if braking is needed.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X1250S
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI50 Standard Cylinder SI50X1250S FAQ
Yes, the SI50X1250S is discontinued. The direct replacement is the AirTAC SAI50X1250S. It shares the identical ISO 15552 mounting interface, 50mm bore, 1250mm stroke, output force, and G1/4 port, fitting directly into existing fixtures.
This double-acting cylinder operates at 30-800 mm/s with a G1/4 port and M16x1.5 rod thread. Force ratings are: 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, and a theoretical maximum of 200 kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X1250S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X1250S replacement — usually within 7-8 hours.